This is the 2671st most frequent Korean word.
수원
"수원" means "water source" or refers to the city of Suwon in South Korea.
In this sentence, '수원' is used as a proper noun referring to the city of Suwon in South Korea.
나는 내일 수원에 갈 예정입니다.
I plan to go to Suwon tomorrow.
Here, '수원' is introduced as the name of the city being described in relation to its location.
수원은 경기도의 도시입니다.
Suwon is a city in Gyeonggi Province.
In this instance, '수원' describes an object associated with the city, namely the historical fortress.